LHASA, Aug. 29 (Xinhua) -- The number of mobile phone users in southwest China's Tibet Autonomous Region has exceeded 2 million.

As of June, Tibet had 2.17 million registered mobile users, accounting for nearly 75 percent of the total population of the high-altitude region, Li Zhen, chief of the region's industry and information technology department, said on Tuesday at a seminar on the region.

There are 402,000 fixed-line phone users and 1.34 million Internet users in the region, added Li.

With total planned spending of 10.2 billion yuan (1.6 billion U.S. dollars) on telecommunication infrastructure construction, the official is expecting the number of mobile and fixed-line phone users to exceed 2.8 million by the end of 2015.

The plateau region is known as "the roof of the world" due to its average altitude of over 4,000 meters, and building telecommunication infrastructures there is more difficult and costly than in other parts of China.

In May 2008, when mankind for the first time took the Olympic flame to the 8,844.43-meter-high Mt. Qomolangma, news reporters traveling with the torch team successfully released photos of the historic moment by mobile phones, marking signal coverage on the world's highest peak.

Rigzin, a 20-year-old Tibetan woman living at the foot of the mountain in the prefecture of Xigaze, said a mobile phone has become one of her most important tools.

She makes phone calls, sends messages and reads news every day through a smartphone she described as "magic."

"My grandpa told me it took 10 days to deliver a letter from here to capital city Lhasa by horse when he was young, but now I can reach my elder brother there within seconds."